The development of the embryonic cardiovascular system begins during the 3rd week of gestation. The process begins with a straight tube, which will eventually differentiate to form a functional heart after several events. Disturbances of any events in the development of the heart, such as cardiac Cardiac Total Anomalous Pulmonary Venous Return (TAPVR) looping, can result in severe congenital Congenital Chorioretinitis disorders. The major clinical presentation Presentation The position or orientation of the fetus at near term or during obstetric labor, determined by its relation to the spine of the mother and the birth canal. The normal position is a vertical, cephalic presentation with the fetal vertex flexed on the neck. Normal and Abnormal Labor of these abnormalities will be cyanosis Cyanosis A bluish or purplish discoloration of the skin and mucous membranes due to an increase in the amount of deoxygenated hemoglobin in the blood or a structural defect in the hemoglobin molecule. Pulmonary Examination.
Last updated: 20 Jan, 2022
The atrial septum begins with endocardial cushions at the base of the atrial chamber and septum primum.
The foramen (ostium) primum is the opening between the 2 embryonic atria.
Image by Lecturio.Endocardial cushions are derived from the neural crest Neural crest The two longitudinal ridges along the primitive streak appearing near the end of gastrulation during development of nervous system (neurulation). The ridges are formed by folding of neural plate. Between the ridges is a neural groove which deepens as the fold become elevated. When the folds meet at midline, the groove becomes a closed tube, the neural tube. Hirschsprung Disease. As the septum primum approaches the dorsal endocardial cushions, cells in the septum undergo apoptosis Apoptosis A regulated cell death mechanism characterized by distinctive morphologic changes in the nucleus and cytoplasm, including the endonucleolytic cleavage of genomic DNA, at regularly spaced, internucleosomal sites, I.e., DNA fragmentation. It is genetically-programmed and serves as a balance to mitosis in regulating the size of animal tissues and in mediating pathologic processes associated with tumor growth. Ischemic Cell Damage, which creates the foramen (ostium) secundum.
Image by Lecturio.The foramen (ostium) primum and secundum function together to deliver oxygenated blood to the left atrium, which will then flow Flow Blood flows through the heart, arteries, capillaries, and veins in a closed, continuous circuit. Flow is the movement of volume per unit of time. Flow is affected by the pressure gradient and the resistance fluid encounters between 2 points. Vascular resistance is the opposition to flow, which is caused primarily by blood friction against vessel walls. Vascular Resistance, Flow, and Mean Arterial Pressure to the left ventricle, whereas, poorly oxygenated blood delivered from the SVC will flow Flow Blood flows through the heart, arteries, capillaries, and veins in a closed, continuous circuit. Flow is the movement of volume per unit of time. Flow is affected by the pressure gradient and the resistance fluid encounters between 2 points. Vascular resistance is the opposition to flow, which is caused primarily by blood friction against vessel walls. Vascular Resistance, Flow, and Mean Arterial Pressure to the right ventricle.
Image by Lecturio.The secundum will grow to narrow the foramen (ostium) secundum and form foramen ovale Foramen ovale An opening in the wall between the right and the left upper chambers (heart atria) of a fetal heart. Oval foramen normally closes soon after birth; when it fails to close the condition is called patent oval foramen. Patent Foramen Ovale. In this case, the septum primum will function as a valve.
Image by Lecturio.Blood from the IVC IVC The venous trunk which receives blood from the lower extremities and from the pelvic and abdominal organs. Mediastinum and Great Vessels: Anatomy pushes the septum primum (valve of foramen ovale Foramen ovale An opening in the wall between the right and the left upper chambers (heart atria) of a fetal heart. Oval foramen normally closes soon after birth; when it fails to close the condition is called patent oval foramen. Patent Foramen Ovale) to move blood from the RA to the LA, after which blood will flow Flow Blood flows through the heart, arteries, capillaries, and veins in a closed, continuous circuit. Flow is the movement of volume per unit of time. Flow is affected by the pressure gradient and the resistance fluid encounters between 2 points. Vascular resistance is the opposition to flow, which is caused primarily by blood friction against vessel walls. Vascular Resistance, Flow, and Mean Arterial Pressure to the left ventricle. At birth, the pressure in the LA will increase, which will shut the foramen ovale Foramen ovale An opening in the wall between the right and the left upper chambers (heart atria) of a fetal heart. Oval foramen normally closes soon after birth; when it fails to close the condition is called patent oval foramen. Patent Foramen Ovale.
Image by Lecturio.Membranous portion of the interventricular septum Interventricular Septum Ventricular Septal Defect (VSD) grows upward to fuse with conotruncal ridges. Right and left ventricles, as well as the aorta Aorta The main trunk of the systemic arteries. Mediastinum and Great Vessels: Anatomy and pulmonary tract, become separated from each other.
Image by Lecturio.Oxygenated blood from the umbilical vein umbilical vein Venous vessels in the umbilical cord. They carry oxygenated, nutrient-rich blood from the mother to the fetus via the placenta. In humans, there is normally one umbilical vein. Prenatal and Postnatal Physiology of the Neonate drains into the IVC IVC The venous trunk which receives blood from the lower extremities and from the pelvic and abdominal organs. Mediastinum and Great Vessels: Anatomy, which also collects the blood from the organs and lower portion of the body; thus, the blood becomes slightly deoxygenated.
Image by Lecturio.Blood from the IVC IVC The venous trunk which receives blood from the lower extremities and from the pelvic and abdominal organs. Mediastinum and Great Vessels: Anatomy pushes the valve of foramen ovale Foramen ovale An opening in the wall between the right and the left upper chambers (heart atria) of a fetal heart. Oval foramen normally closes soon after birth; when it fails to close the condition is called patent oval foramen. Patent Foramen Ovale and flows into the left side of the heart, where it mixes in the LA with deoxygenated blood from the pulmonary veins Veins Veins are tubular collections of cells, which transport deoxygenated blood and waste from the capillary beds back to the heart. Veins are classified into 3 types: small veins/venules, medium veins, and large veins. Each type contains 3 primary layers: tunica intima, tunica media, and tunica adventitia. Veins: Histology. Blood then leaves the heart through the aorta Aorta The main trunk of the systemic arteries. Mediastinum and Great Vessels: Anatomy and flows to the iliac arteries Arteries Arteries are tubular collections of cells that transport oxygenated blood and nutrients from the heart to the tissues of the body. The blood passes through the arteries in order of decreasing luminal diameter, starting in the largest artery (the aorta) and ending in the small arterioles. Arteries are classified into 3 types: large elastic arteries, medium muscular arteries, and small arteries and arterioles. Arteries: Histology, which are connected to the placenta Placenta A highly vascularized mammalian fetal-maternal organ and major site of transport of oxygen, nutrients, and fetal waste products. It includes a fetal portion (chorionic villi) derived from trophoblasts and a maternal portion (decidua) derived from the uterine endometrium. The placenta produces an array of steroid, protein and peptide hormones (placental hormones). Placenta, Umbilical Cord, and Amniotic Cavity by the umbilical arteries Arteries Arteries are tubular collections of cells that transport oxygenated blood and nutrients from the heart to the tissues of the body. The blood passes through the arteries in order of decreasing luminal diameter, starting in the largest artery (the aorta) and ending in the small arterioles. Arteries are classified into 3 types: large elastic arteries, medium muscular arteries, and small arteries and arterioles. Arteries: Histology. However, blood from the SVC flows directly into the RV and then to the pulmonary trunk Pulmonary Trunk Truncus Arteriosus, which is connected to the descending aorta Descending aorta Mediastinum and Great Vessels: Anatomy through the ductus arteriosus Ductus arteriosus A fetal blood vessel connecting the pulmonary artery with the descending aorta. Patent Ductus Arteriosus (PDA).
Image by Lecturio.After birth, the ductus arteriosus Ductus arteriosus A fetal blood vessel connecting the pulmonary artery with the descending aorta. Patent Ductus Arteriosus (PDA) becomes the ligamentum arteriosum Ligamentum arteriosum Prenatal and Postnatal Physiology of the Neonate, as blood is able to enter the lungs Lungs Lungs are the main organs of the respiratory system. Lungs are paired viscera located in the thoracic cavity and are composed of spongy tissue. The primary function of the lungs is to oxygenate blood and eliminate CO2. Lungs: Anatomy to be oxygenated. The foramen ovale Foramen ovale An opening in the wall between the right and the left upper chambers (heart atria) of a fetal heart. Oval foramen normally closes soon after birth; when it fails to close the condition is called patent oval foramen. Patent Foramen Ovale closes and becomes the fossa ovalis Fossa ovalis Prenatal and Postnatal Physiology of the Neonate due to increased pressure in the LA.
Image by Lecturio.After birth, the umbilical artery Umbilical artery Specialized arterial vessels in the umbilical cord. They carry waste and deoxygenated blood from the fetus to the mother via the placenta. In humans, there are usually two umbilical arteries but sometimes one. Prenatal and Postnatal Physiology of the Neonate becomes the ligamentum teres Ligamentum teres A cord-like remnant structure formed from the closed left fetal umbilical vein. It is located along the lower edge of the falciform ligament. Liver: Anatomy hepatis, whereas the umbilical vein umbilical vein Venous vessels in the umbilical cord. They carry oxygenated, nutrient-rich blood from the mother to the fetus via the placenta. In humans, there is normally one umbilical vein. Prenatal and Postnatal Physiology of the Neonate becomes the medial umbilical ligament.
Image by Lecturio.Mnemonic: right-to-left shunts (cyanotic lesions) (the 5 Ts):